Cellulose food casings in the form of tubes are well known in the art. They are of several types and sizes to accommodate the many types of food products which are processed and/or packaged in such casings.
One type of cellulose casing, commonly referred to as "fibrous casing" has a fibrous support web, usually paper, imbedded in the casing wall. Casings of this type generally are used in the preparation of larger diameter food products such as bologna and the like. Fibrous casing also is used in the production of sausage products of the type that are hung for cooking, drying or other processing. Products of this type for example include pepperoni and salami among others.
Fibrous casings are sold either as so called "cut lengths" or in shirred form. Cut-lengths are single pieces of casing of from about 1.52 to about 2.43 meters long which are provided in a flattened condition and which are suitable for making one or, at most, a few stuffed products. One end of the cut length of casing usually is preclosed with a clip or tie by the casing supplier as a convenience to the casing user. Also, if the cut length end use is to produce a sausage which is hung for processing, the casing supplier usually attaches a loop at the preclosed end. Generally this loop is kept as short as possible in order to make maximum use of the vertical space in the chambers where the stuffed casing is hung for processing.
A "shirred" casing is a much longer length of casing (30 meters and more) which has been gathered and pleated by mechanical means to form a shirred tube of casing. Shirred casings are used for producing a plurality of stuffed product lengths one after another on an automatic stuffing machine.
Casings generally are identified by size which represents a stuffing diameter recommended by the casing manufacturer for that particular casing. This recommended stuffed diameter (RSD) corresponds to a stuffed circumference which is greater than twice the flat width of the casing. Thus, the casing must be stretched circumferentially during stuffing to reach its RSD.
Both types of fibrous casing require a certain minimum moisture content to provide the casing with the flexibility and extensibility required for stuffing to the casing RSD. For shirred fibrous casings this moisture content either is added in controlled amounts by the casing manufacturer prior to shirring so it contains at least the minimum moisture needed for stuffing and is ready to stuff, or the casing is soaked in warm water, usually to saturation, by the casing user shortly prior to stuffing. Soaking by the user is the commonly accepted way of adding moisture to cut length casing.
After soaking, the flat cut length is gathered manually onto a stuffing horn. Gathering the flat wet casing onto a stuffing horn in this fashion is difficult, particularly for the sizes of casing as used in the production of pepperoni or other products having a stuffed diameter comparable to pepperoni i.e. about 40-50 mm. This is because the casing diameter is relatively small compared to the length of the casing and is not much larger than the stuffing horn diameter. Consequently when the flat wet casing is gathered onto the horn, the casing tends to cling to the horn surface. Also, since a cut length of casing usually is closed at one end, care must be taken to insure the interior of the casing is vented. Otherwise, the operation of gathering the casing onto the horn creates a partial vacuum within the casing which causes the casing to be pressed against the horn surface by atmospheric pressure. This further impedes the gathering of the full length of the casing onto the stuffing horn.
A shirred tube of casing is easier to position onto a stuffing horn. This is because the shirred tube has an open bore which facilitates entry of the stuffing horn into the casing and the shirred length is considerably shorter than the casing length. However, when shirred casing is soaked or otherwise moisturized by the casing user the added water swells the casing. This causes the shirred tube to expand longitudinally and the gathered pleats tend to separate so the shirred tube loses its integrity. To prevent this loss of longitudinal integrity and facilitate loading the moisturized shirred tube onto a stuffing horn, a common practice is to provide either an internal or external restraint to prevent longitudinal expansion of the fibrous casing as the casing imbibes moisture.
For example, a conventional internal restraint for shirred casing includes a plastic tube which extends through the bore of the shirred casing with washers or pegs at each end to hold the shirred casing in place on the plastic tube. A conventional external restraint generally is a net or perforated plastic shrink film which encompasses the entire outer surface of the shirred casing including at least a portion of its opposite ends.
The so called "tube and peg" internal restraint is not appropriate for use where one end of the casing is preclosed and conventional external restraints create an element of waste after removal.
The present invention provides a casing article which contains a length of casing comparable to a cut length. It requires the addition of moisture prior to stuffing yet is easier to load onto a stuffing horn than a conventional cut length, and it avoids the use of conventional internal or external restraints commonly used for shirred casings.